Morphological study of larval development and the transition to juvenile stage in thin-lipped mullet, Liza ramada

Abstract

Introduction: The detailed description of larval and juvenile stages of L. ramada is so far lacking.Aim of the Work: The present study aimed to describe larval development and the morphological transition to the juvenile stage in L. ramada after artificial spawning.Material and Methods: In this study, we described early development of Liza ramada over the early rearing period of 63 days post-hatching.Results: The newly hatched larvae have closed mouth and anus. At seven days post-hatching, the larvae have opened mouth and both yolk sac and oil globules disappeared. At 14 days, larvae have a distinct fins and increased skin pigmentation. At 21 days post-hatching, the larvae have variable coloration with more density. At 28 days post-hatching, the body depth of larvae increased and the stomach contains some food indicating the larval ability to digest external food. In 35 days-old larvae, the eyes become fully pigmented. At 42 days post-hatching, the larvae have high density of pigmentation all over the body and transparent caudal fin with rays. At 49 days post-hatching, the body of juvenile is distinctly elongated and laterally compressed with obvious scales. By 56 days post-hatching, the fish is covered with scales and well-developed rays. At 63 days post-hatching, the body becomes large and completely covered with scales and high density of pigmentation. The larvae begin transformation to juvenile stage at 42 days post-hatching and then finished the transformation at 63 days post-hatching. Importantly, the juvenile stage of L. ramada can be handled safely at 63 days post-hatching.Conclusion: The juvenile’s production of L. ramada requires a period of 63.